Magnetic spatula



Feb. 10, 1959 E. L. BENNET MAGNETIC SPATULA Filed Oct. 7. 1955 United States Patent MAGNETIC SPATULA Eugene L. Bennet, St. Joseph, Mich., assignor to Laboratory Equipment Corporation, St. Joseph, Mich, a corporation of Michigan Application October 7, 1955, Serial No. 539,144

6 Claims. (Cl. 29465.5)

The present invention relates to a novel magnetic spatula.

One of the objects of my invention is to provide a spatula which is extremely useful in picking up and dropping small steel screws, other steel parts, or small iron or steel particles for instance.

A further object of my invention is to provide a novel device of the above character which picks up such objects by means of magnetic attraction and in which the amount of the magnetic attraction is readily adjustable by the user.

Still another object is to provide a novel spatula which is useful in weighing out test samples of small particles of magnetic material for analytical purposes.

And another object is to accomplish the above at low cost.

Other objects and advantages will become apparent from the following description of a preferred embodiment of my invention, which is illustrated in the accompanying drawings.

In the drawing, in which similar characters of reference refer to similar parts throughout the several views,

Fig. 1 is a top view of a magnetic spatula embodying features of the present invention, shown with one-half of the handle removed so as better to illustrate the internal structure; 7

Fig. 2 is a side view of the device of Fig. 1 with the near side half of the handle removed so as to illustrate the interior structure in greater detail;

Fig. 3 is a perspective view of the blade of the spatula; and

Fig. 4 is a perspective view of the portion of the apparatus which magnetizes the spatula of Fig. 3.

In analyzing steel or iron for carbon or sulfur content for instance, it is conventional practice to provide the metal to be tested in the form of small particles, such as turnings, drillings, or the like. Individual samples to be analyzed are then weighed out from these particles to provide a definite mass of material, such as a onegram sample or a half gram sample, so that the analytical apparatus can be calibrated to read directly, thus avoiding mathematical calculation.

' Ordinarily this is accomplished by picking up a quantity of the material upon a spatula, and tapping the spatula to shake material therefrom onto the weighing pan until the predetermined quantity rests thereon.

The spatula of the present invention picks up a quantity of material to be weighed by magnetic attraction and the particles are dropped from the end of the spatula onto the weighing pan by gradually decreasing the magnetism of the spatula. This it has been found gives a much more precise control of the operation than does the tappingmethod and is considerably faster.

The device of this invention is also useful for picking up small screws and other small steel objects and drop ping them into place. It is therefore useful in servicing watches and other small instruments for instance. Other 2,873,136 Patented Feb. 10, 1959 uses for the device of the present invention will become apparent from the following description of a preferred embodiment.

By referring to the drawings, it will be seen that the device there illustrated is comprised essentially of three basic elements. One of these is a spatula blade 10 formed of mild steel for instance. Mild steel is a magnetic material of low retentivity.. This is attached to a nonmagnetic handle 12 which may be formed of a suitable plastic substance. I For convenience in assembly, the handle is formed in two halves (one shown at 13) which are substantially reverse complements of each other. In addition to the blade and the handle, there is a magnetic member 14 which consists of a small cylindrical magnetic slug 16 attached at its center to the center of a handwheel 18. The slug 16 is magnetized in such fashion that the poles are on opposite diametrical sides thereof rather than being at the ends as is usual with bar magnets. The handwheel 18 may be formed of a washer type element of plastic or other nonmagnetic material which is cemented to the center of the cylindrical slug 16 as is best seenin Fig. 4. If desired, of course, the wheel portion can be molded directly upon the magnetic member. The two halves of the handle are secured together by a pair of screws 20.

More specifically, the spatula blade 10 is rather long and arrow, much like the blade of a standard spatula, but near the rearward end thereof it is formed to provide a longitudinally extending slot 22, and at each side of the slot the narrow strips of the metal which define the slot are shaped to approximately hemicylindrical contour transversely as is indicated at 24. This transverse groove 24 has substantially the same radius of curvature as does the cylindrical magnetic slug 16.

The magnetic member 14 is located with respect to the spatula blade 10 so that the handwheel 18 lies within the slot 22 with the two projecting ends of the slug 16 resting in the depression 24. As the wheel 18 is rotated, therefore, it will be seen that in one position, with the north poles in contact with the metal in the depressions 24, the spatula blade will be magnetized so as to have a north polarity. If the handwheel 18 is rotated 180 it will be apparent that the spatula blade will have a south polarity. Halfway between these two positions the north and south poles will both be in equal engagement with the metal defining the groove 24, and thus the spatula blade 10 will have no magnetic polarity.

The two halves of the handle are so formed that when they are in face to face relation there is a longitudinal slot 26 extending therethrough from top to bottom which provides clearance for the handwheel 18 and allows a portion of the circumference of the handwheel to project above the top or bottom, or both surfaces of the handle, as is best seen in Fig. 2. The handle members also provide aligned transversely extending cylindrical pockets which confine and journal the cylindrical ends of the magnetic slug 16. The handle members when assembled also provide a thin horizontal slot which extends inwardly from the forward end thereof for the purpose of confining the rearward portion of the blade 10 up to a position slightly ahead of the forward end of the slot 22. The two handle halves are held together by a pair of screws 20.

The spatula is easily assembled by placing the magnetic element 14 into position near the rearward end of the blade 10 and then pressing this subassembly in an edgewise direction into one of the handle halves. Thereafter the other handle member is pressed into position, so that the two halves are in close engagement with each other. The screws 20 are thereafter inserted and tightened to complete the article.

In use, the operator holds the handle in his hand and V rotates the wheel 18 with his thumb or finger so as to magnetize the blade by bringing either the north or south magnetic pole into engagement with the metal of the blade. The end of the spatula is then dipped into the iron or steel particles to be weighed, thereby causing a mass of the particles to cling to the end ofthe spatula. The spatula is then moved so that the end is positioned above theweighing pan and the handwheel 18 isslowly rotated to gradually reduce the magnetism of the blade thus causing the particles to drop at the desired rate ontothe weighing pan. When the scale beam is in balance, the handwheel may be rotated slightly in the reverse direction to cause the particles remaining attached thereto to cling more tightly. The spatula can then be moved away from the pan without danger of spilling additional particles from the blade.

It will be appreciated that approximately the same technique is used for picking up small screws or other parts, excepting that ordinarily the thumb wheel can be rotated from the position where the spatula blade is magnetized, to a position where the blade is sutficiently demagnetized to release the steel part rather abruptly, since a slow, progressive 'demagnetism of the blade is not essential.

With the device of this invention, residual magnetism of either the blade or the particles adhering thereto raises no problem. The reason for this is as follows: When the thumb wheel is rotated reversely to drop the metal particles, it will eventually reach a position Where the north and south poles of magnet 14 are in equal engagement with the blade 10. The magnet, therefore, has no magnetizing effect upon the blade, but some particles may still cling to the blade because of residual magnetism. However, continued rotation of the wheel in the same direction automatically reverses the polarity of the blade so that what few particles cling by residual magnetism are eventually repelled from the blade. This of course takes place automatically without the user even being aware of the reversal of blade polarity, since rotational movement of the control wheel is continuously in the same direction.

From the above description of a preferred embodiment of my invention it will be appreciated that substitutions and variations in the structure may be made without departing from the spirit or scope of the invention and that, therefore, the scope of, the invention is to be measured by the scope of the accompanying claims.

Having described my invention, What I claim as new and useful and desire to secure by Letters Patent of the United States is:

1. In a spatula: a handle, a diametrically magnetized cylindrical permanent magnet disposed within said handle and journaled for rotation about its cylindrical axis, a blade formed of magnetic material, one end of said blade being free and the other end thereof extending into said handle to a position such that it touches a portion of the cylindrical surface of said magnet so that rotation of said magnet about its cylindrical axis changes the disposition of the poles of said magnet relative to said blade, and means for rotating said magnet.

2. A spatula comprised of a blade formed of magnetic material, a handle attached to one end of said blade, a rotatable permanent magnet rotatably mounted on said handle in contact with said blade, said magnet having a pair of spacedmagnet-ic poles of opposite polarity located on diametrically opposite sides of the magnet with respect to the axis of rotation of the magnet, and means for rotating said magnet relative to said blade to cause one of said magnetic poles to contact said blade when the last said means is in one position and to cause both of said magnetic poles to contact said blade when the last said means is in another position.

3. In a spatula, a blade formed of a magnetic material, a diametrically magnetizedcylindrical permanent magnet, one end of said blade being formed to provide a groove in one face thereof, said magnet being disposed in said groove with the cylindrical axis of said magnet extending along said groove, said groove having an effective depth for receiving said magnet which is limited to the radius of the magnet, a handle enclosing said magnet and said one end of said blade, and operating means coacting with said magnet and projecting beyond the surface of said handle for rotating said magnet about its cylindrical axis. 7 V

4. A spatula for handling small magnetic bodies, com; prising, in combination, a handle, a magnetic element of low retentivity supported on said handle, said magnetic element including "a blade portion projecting from said handle, a permanent magnet movably supported on said handle and having two magnetic poles of opposite polarity spaced from each otherfand manual operating means coactin'g with said magnet to move the latter relative to said magnetic element to carry one pole of the magnet into and out of close proximity to said magnetic element.

5 A spatula for handling small magnetic elements, comprising, in combination, a handle, a magnetic element of low retentivity supported on said handle, said magnetic element including, a blade portion thereof projecting from said handle, a permanent magnet having two magnetic poles of opposite polarity spaced from each other, means on said handle movably supporting said magnet and defining a path along which said magnet can be moved relative to said magnetic element to bring said respective magnetic poles of the magnet alternately into and out of close proximity to said magnetic element, and manual operating means coacting with said magnet to move the latter through said path of movement thereof.

6. A spatula for handling small magnetic bodies, comprising, in combination, a first magnetic element shaped to form a spatula blade, said first magnetic element being formed of a magnetic material of low retentivity, a second magnetic element comprising a permanent magnet having two magnetic poles of opposite polarity spaced from each other, a non-magnetichandle, means on said handle supporting one of said magneticjelements, means on said handle movably supporting the other of said magnetic elements and defining a path of movement of said other magnetic element relative to said one magnetic element which carries one pole of said permanent magnet into and out of close proximity to said first magnetic element, and manual operating means coacting With said other magnetic element to move the latter through said path of movement thereof relative to said one magnetic element.

No references cited. 

